Charles b



April 27, 1926.

C. B. STEVENS PROCESS AND APPARATUS FOR FORMING IMPREGNATED SHEETS Filed Jan. 6, 1922 Jnuculoz @Hmucql Patented Apr. 27, 1926.

UNITED STATES oFFic CHARLES B. STEVENS, OF NEW YORK, N. Y.

Application filed January 6, 1922.

To all 'w/mm it mag concern Be it known that I, CHARLES B. STEVENS, acitizen of the UnitcdStatcs, residing at 116 East 53rd St, city of New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Processes and Apparatus for Forming Impregnated Sheets, of which the following is a specification.

This invention relates to the manufacture of sheets or slabs comprising a fibrous material and a binder, one object of the invention being the provision of a mechanical device or machine by which a fibrous body,

usually but not necessarily in the form of a' pre-formed bat, felt, sheet, web or woven fabric, may be uniformly impregnated with any appropriate binder, such as gelatine, viscose or the like. Uniform impregnation, as the term' is employed herein, implies not only an impregnation of every portion of the fibrous body '(hereafter for convenience referred to simply as the bat), but impregnation witha practically uniform quantity of'binder per surface unit of the hat. The invention comprises also the novel process involved in the operation of the machine. The impregnated sheets or slabs resulting from the operation are useful for many purposes, including the manufacture, by further processing, of artificial leather or leather substitutes, of floor coverings or the like.

It may be explained that although it is quite possible for a skilled operator, using a hand trowel or similar device, to impregnate uniformly a given area of fibrous sheet, it is exceedingly diflicult to secure the same result by purely mechanical appliances. This is particularly the case, when, as in the manufacture of artificial leather or leather substitutes, the perfection of the surface, and its freedom from flecks or protruding fibers, becomes of importance. Dipping processes are asa rule inapplicable because of lack of accurate control of the degree of saturation; and processes involving the use of rolls are unsatisfactory on account of the tendency of the impregnated bat to stick to the rolls, and also because of surface defects due to suction caused by the roll action.

. According to the present invention, in its preferred embodiment, the bat, supported upon a belt or like device in continuous movement, is treated at one, or preferably both surfaces with the impregnating liquid,

Serial No. 527,425.

the quantity of liquid delivered in unit time being so controlled with reference to the rate of movement of the bat as to secure exactly the desired degree of saturation, having regard to the use to which the impregnated bat is to be applied. The impregnated bat is then subjected to a mechanical operation or series of operations which are conveniently described as troweling, the purpose of which is to secure a practically uniform distribution of the binder throughout the fibrous body on the one hand, and to impart a perfect surface on the other. In my preferred apparatus I secure these results by causing the bat, following the first treatment of its upper and lower surfaces with the impregnating binder, to pass under a plurality of wiping devices or trowels spaced along the line of movement, the effect of which, referred to any given area of the bat, is to subject it to any desired number of intermitting wiping pressures, each followed by a period of release, and at the same time repeatedly to smooth the surface. The arrangement is such that not only may the degree and duration of each pressure be accurately and readily controlled but the number of successive pressures as well as the interval between pressures may be varied as may be required for the best results with any particular material. The whole operation may be made to simulate closely the hand-trowelling of a skilled operator.

For a full understanding of my invention reference is made to the accompanying drawings illustrating a typical and preferred embodiment of the same.

In said drawings- Fig. 1, is a vertical longitudinal section of the trowelling apparatus, the central portion being broken away;

Figs. 2 and 3 show, on a larger scale the Shoe which is applied to the end of the bat,

and

Fig. 4, is a detail view of a modified form of means for weighting the trowels.

Referring to Fig. 1, A is a table or stand. B is an endless belt which passes over the flat top of the table, and is driven by rolls 1, 2 which are in turn driven from any suitable source of power such as a motor 3. The belt is made of a width in accordance with the width of the material to be saturated. The saturating fluid may be delivered from the tank 4, by a pump 5, actuated by the motor 6. From the pump the the impregnated liquid to the top of the bat; and, if required, a third sprinkler 9 or several additional sprinklers, deliver ad-. ditional material to the upper side of the bat. After the bat has passed between the two sprinklers 7 and 8 it passes underneath a trowel or a series of trowels 12, as many being used as are necessary to obtain the desired result.

The successive operations of sprinking and trowelling which are repeated as often as are necessary, result in a thorough impregnation of the bat.

The bat leaves the end of the table at a point where the belt passes over the pulley 2 and drops on to a second belt or conveyor C by which the material is conveyed away.

In order that the bat may be conveyed uniformly with the same speed as the belt, and at the same time eliminate any possibility of the edge curling up behind any one I of the trowels at the point of impact, a de vice is attached along the full edge of the bat before it is delivered to the table, this device being in the form of a wedge shaped shoe 13-which forms a protection to the edge of the material, which will readily slide under the trowels 12. The shoe 13 may be made of any suitable material and is sufficiently resilient to enable its ready attachment to the bat. At its back end the shoe is turned up underneath the material to form a square edge or lug against which a cleat or lug 14 attached to the belt B will engage and push forward the shoe and its attached bat at the same speed that the belt is traveling. The cleats or lugs 14 may be placed at frequent intervals on the belt and may be either arranged continuously across the belt or divided up into two or more sections. They may also be made in the shape of upright arms attached to the edge of the belt in such manner as to engage the shoe. This arrangement insures a uniformity in speed of the movement of the bat, and proper centering of the same on the conveyor, and an easy passage of the edge under the trowels. The shoe also serves as a weight to carry the bat from the belt B to the belt C on which it is uniformly deposited and centered. The belt C may also have lugs 15 similar to those on belt B in order to again insure conveyance at the same speed without slippage on the second carrier.

The" belt B may be made of rubber, leather, canvas which is parafiin-coated or otherwise liquid proofetl, or any other fabric, mesh or material, woven or otherwise.

which is best adapted to the material being coated and the liquid or solution which is used. The belt need not be liquid proof if means are provided beneath it to hold the liquid until it is absorbed. The belt may be made of metal screen or mesh or metal plates coupled or linked together, and a trough may be provided at the sides of the belt to recover excess solution in cases where super-saturation is advisable.

The trowels 12 are preferably made of pieces of light sheet metal which may be flexible or non-flexible, bent to a contour which will ease the impact of the shoe and the material passing beneath, the lower portion of the trowel sloping forward so that the toe is that part which is most in contact with the bat. At the point of contact the trowel is rounded upward in order to accomplish the double object of graduating the amount of surface area pressing or trowelling against the bat and also of preventing the bat from dragging under a blunt edge which might cause a fracture of the surface. The sheet metal trowel thus shaped is wide enough to lie across the full width of the material and may be made in one piece or divided into several sections. The sheet metal so formed is attached to a rod, of greater length than the width of the trowel which may at the upper end, have an adjustment so that the trowel may hang from the red at the desired pitch. The rod with the attached trowel is then hung from side rails 20 arranged above the plane of the table andprovided with notches or slots 18 into which the ends of the rods can be placed and from which they can be readily removed.

In order to control the pressure that it may be desired to put upon the material when passing under the trowels, a bar 17 of the desired weight may be laid upon the trowel. Bars of different diameter and weight may be used so that the pressure applied is easily graduated and is evenly distributed across the entire length of the trowel. The pressure applied may also be governed by the weight of the trowel itself or weights of other character. Should it be desired to gradually increase the pressure of the trowels on the material a gradually increasing number of bars or bars of increasing diameter may be laid upon the successive trowels. A modified form of trowel weighting device is shown in Fig. 4 in which the trowel is provided with an arm 18 having thereon an adjustable weight 19.

Trowels may be composed of any material other than sheet metal such as wood, papicrmach, glass,.porcelain, rubber, leather, or

lili) 4 as desired by rolling or otherwise.

a composition of any hllKl." They may also have a contour different from that described such as semi-circular, elliptical or any other form which may accomplish the same object.

It will be noted that the pivotal mounting of the trowels or Wiping devices permits the pressure exerted by each to be individually varied, by adding or removing weights in the form of rods or other convenient shape; also that the arrangement is such that the positions of the trowels may be varied at will alongthe line of movement of the hat by merely shifting from one set of supporting recesses to another. Furthermore, in the specific embodiment of the invention chosen for illustration the effect of the addition or removal of the weights is to vary the angu lar position of the trowels with reference to the surface of the bat, with corresponding variation of the wiping or t-rowelling effect. Thisreadiness of control of the trowelling conditions at each point is an important advantage of the apparatus.

\Vhile in the above described embodiment of my invention the impregnating liquid is supplied to a pre-formed bat, comprising for example cotton fibers, my invention is not limited to this procedure. For example, a fibrous material or filler may be fed to the carrier along with the binder, the mixture being then consolidated and formed by the trowels into a sheet or slab, which may be later further consolidated and compacted Inthis Way it is possible for example to form slabs comprising ground cork or wood pulpor ground leather, with a binder of gelatine, viscose or other suitable material. Or, alternatively, the fibrous material or other filler may be impregnated in bulk with a part or all of the'binder required for the particular purpose in view and the resulting mixture may then be formed into sheets or slabs in any approved way, and fed to the trowel system, further quantities of binder being supplied if and as required.

I claim 1. In a process of forming impregnated sheets, subjecting a moving sheet, comprising a fibrous body and a binder, to intermittent trowelling.

2. In aproc'ess' of forming impregnated sheets, the steps comprising supplying an impregnating liquid to opposite faces of a moving bat, adjusting the flow of liquid with reference to the rate of movement of the bat to secure the desired degree of saturation and then subjecting the impregnated bat to intermittent trowelling.

3. Apparatus, for forming impregnated sheets, comprising in combination a carrier for the impregnated material and wiping means spaced along the line of movement of said material said wiping means being adjustable along said line of movement.

4. Apparatus for forming impregnated sheets, comprising in combination a carrier for the material to be impregnated, n'ieans for supplying an impregnating liquid in said material, and wiping means spaced along the line of movement of said material said wiping means being adjustable along said line of movement.

5. Apparatus for forming impregnated sheets, con'iprising in con'ibimition a carrier for the material to be impregnated. means for supplying an impregnating liquid to said material, at opposite surfaces thereof, and wiping means spaced along, the line of movement of said material said wiping means being adjustable along said line of movement.

6. Apparatus for forming impregnated sheets comprising in combination a carrier for the material, wiping means spaced along the line of movement of said material, and means for varying the pressure exerted by said wiping means.

7. Apparatus for forming impregnated sheets, comprising in combination a carrier for the material to be impregnated, means for supplying an impregnating liquid to said material, wipng means spaced along the hue of movement of said material, and means for varying the pressure exerted by said wiping means.

8. Apparatus for forming impregnated sheets, comprising in combination a carrier for the material, wiping means spaced along the line of movement of said material, and means for varying the angular position of said wiping means.

9. Apparatus for forming impregnated sheets, comprising in combination a carrier for the material to be impregnated, means for supplying an impregnating liquid to said material, wiping means spaced along the line of movement of said material, and means for varying the angular position of said Wiping means.

10. Apparatus for forming impregnated sheets, comprising in combination a carrler for the material, wiping means spaced along the line of movement of said material, and means for varying the angular position of said wiping means and the pressure exerted thereby.

11. Apparatus for forming impregnated sheets, comprising in combinatlon a carrier for the material to be impregnated, means said material, wiping means spaced along the line of movement of said material, and means for varying the angular positlon of said wiping means and the pressure exerted thereby. U

12. Apparatus as claimed in cla1m 3 com prising a belt carrier, :1. shoe for engag ng the front edge of the material, and means on the belt for engaging the shoe.

for supplying an impregnating liquid to 13. Apparatus as claimed in claim 3 in which the \vi ing means are bent sheets attached to ro s, and notched rails are provided for supporting the rods.

let. Apparatus as claimed in claim 3 in which the wiping means are bent sheets attached to rods and means are provided for applying pressure to the Wiping means consisting of rods located on the sheets and notched rails are provided for supporting the first named rods.

15. Apparatus for forming impregnated sheets comprising a carrier belt, a table over which such belt passes, means for delivering 15 material to the belt, wiping means comprising bent sheets having pivots at their upper ends, and supporting means for said pivots.

16. Apparatus for forming impregnated sheets comprising a carrier belt, a table over which such belt passes, means for delivering material to the belt, means for supplying an impregnating liquid to said material at opposite surfaces thereof, wiping means comprising bent sheets having pivots attheir upper ends, and supporting means for said pivots.

In testimony whereof, I affix my signature.

CHARLES E. STEVENS. 

